As a gas exchanger that removes gas components from a liquid or transfers gas components to make them dissolve in a liquid, those utilizing hollow fiber membranes are used. Hollow fiber membranes are used as a module in which multiple hollow fiber membranes are bundled and caps are provided on both ends. Such module is used in such a manner that a liquid is caused to flow through the hollow fiber membranes, and a gas contained in the liquid is removed by external aspiration, or a gas is caused to blend into the liquid in the hollow fiber membranes by pressurizing an external gas (see Japanese Patent No. 3370407 publication).
One exemplary total organic carbon measuring instrument for measuring total organic carbon in a sample water is equipped with an organic compound oxidative decomposing part for converting organic carbon into carbon dioxide; a carbon dioxide extracting part for extracting carbon dioxide generated in the organic compound oxidative decomposing part into pure water; and a detecting part for detecting conductivity of pure water in the carbon dioxide extracting part for quantifying the carbon dioxide extracted in the carbon dioxide extracting part.
In such a total organic carbon measuring instrument, for transferring carbon dioxide from a sample water having been subjected to oxidation process in the organic compound oxidative decomposing part into pure water, in the carbon dioxide extracting part, the sample water and the pure water are arranged with a gas permeable membrane or a porous membrane intervened therebetween so that carbon dioxide in the sample water is transferred into the pure water via the gas permeable membrane or the porous membrane.